CN109326216B

CN109326216B - Display device with rollable display panel

Info

Publication number: CN109326216B
Application number: CN201810844214.5A
Authority: CN
Inventors: 金正勳; 金峰澈
Original assignee: LG Display Co Ltd
Current assignee: LG Display Co Ltd
Priority date: 2017-07-31
Filing date: 2018-07-27
Publication date: 2021-05-07
Anticipated expiration: 2038-07-27
Also published as: JP6612938B2; US20190037716A1; JP2019028461A; DE102018118372A1; KR102332710B1; CN109326216A; TWI686643B; TW201910878A; KR20190013001A; US10701821B2

Abstract

A display device having a rollable display panel, comprising: a rollable display panel for displaying an image; a display panel roller to which the display panel is fixed, the display panel roller being elongated; a support frame to which the display panel roller is rotatably coupled; a driving motor for rotating the display panel roller with respect to the support frame, wherein the rotation of the display panel roller causes the display panel to be wound up on the display panel roller or unwound down from the display panel roller; and an elastic unit for providing an elastic force to assist in winding up the display panel on the display panel roller. This allows the size or capacity of the motor to be reduced.

Description

Display device with rollable display panel

Technical Field

The present invention relates to a display device having a rollable display panel.

Background

As information technology has been gradually developed, the market of display devices as communication means for delivering information to users has been gradually increased. In this regard, display devices such as Organic Light Emitting Displays (OLEDs), Liquid Crystal Displays (LCDs), and Plasma Display Panels (PDPs) are increasingly employed.

An Organic Light Emitting Display (OLED) includes a display panel having a plurality of sub-pixels and a driver for driving the display panel. The driver includes a scan driver for supplying a scan signal or a gate signal to the display panel and a data driver for supplying a data signal to the display panel.

Organic Light Emitting Displays (OLEDs) may have flexibility. Thus, the display panel thereof may be bent or curved. In addition, the display panel may be wound in a roll shape (roll shape) and then may be unfolded in a planar shape. In recent years, various structures have been designed to accommodate flexible display panels of Organic Light Emitting Displays (OLEDs).

Disclosure of Invention

This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify all key features or essential features of the claimed subject matter, nor is it intended to be used alone to determine the scope of the claimed subject matter.

An object of the present invention is to provide a display device having a rollable display panel that is rolled up and unrolled down using a driving motor.

Another object of the present invention is to miniaturize the size of a driving motor in a display device having a rollable display panel using an elastic unit.

To this end, according to the present invention, there is provided a display device comprising: a rollable display panel for displaying an image; a display panel roller to which the display panel is fixed, the display panel roller being elongated; a support frame to which the display panel roller is rotatably coupled; a driving motor for rotating the display panel roller with respect to the support frame, wherein the rotation of the display panel roller causes the display panel to be wound up on or unwound down from the display panel roller; and an elastic unit for providing an elastic force to assist in winding up the display panel on the display panel roller.

In one embodiment, the driving motor and the elastic unit are disposed in the display panel roller and are respectively disposed at positions adjacent to opposite ends of the elongated display panel roller.

In one embodiment, the display device further includes a weight lever coupled to the display panel at a bottom of the display panel.

In one embodiment, the elastic unit serves to store elastic force during the process that the display panel is unwound downward from the display panel roller, and release the stored elastic force to assist in winding up the display panel on the display panel roller.

In one embodiment, the elastic unit comprises a torsion spring.

In one embodiment, the elastic unit includes: a hollow shaft connected to the support frame; and a torsion spring having one end fixed to the hollow shaft and the other end fixed to the display panel roller.

In one embodiment, the tension of the torsion spring is adjustable by adjusting the fixing state of the hollow shaft.

In one embodiment, a circuit board is disposed in the display panel roller between the driving motor and the elastic unit, wherein the wire connected to the display panel is drawn out of the display panel roller through the elastic unit.

In one embodiment, the elastic unit comprises a compression spring.

In one embodiment, the elastic unit includes: a spring housing secured to the support frame; a compression spring disposed within the spring housing; a compression plate coupled to the compression spring to be axially slidable along the spring housing within the spring housing; a ball screw coupled to the compression plate; and a ball nut fixed to the display panel roller, wherein the ball screw is threadedly coupled to the ball nut.

In one embodiment, the ball screw is hollow such that wiring connected to the display panel passes through the ball screw.

In one embodiment, the display device further includes a sensor for sensing a degree of rotation of the display panel roller.

According to the present invention, the display panel may be wound up or unwound down using a motor. Thus, the display device of the present invention can be used more conveniently.

Further, according to the present invention, when the display panel roller rotates such that the display panel descends, elastic force is stored in the elastic unit. Then, the elastic force stored therein relieves the required power of the display panel roller for winding up the display panel. This allows the use of a relatively small capacity or size drive motor.

Drawings

Fig. 1 is a schematic block diagram of an organic electroluminescent display device according to an embodiment of the present invention;

FIG. 2 shows a schematic circuit diagram of a sub-pixel;

FIG. 3 shows an example of a sub-pixel configuration according to an embodiment of the invention;

FIG. 4 is a plan view of a display panel according to an embodiment of the present invention;

FIG. 5 is a cross-sectional view of a display panel according to an embodiment of the present invention;

fig. 6 is a sectional view showing an etching example of the first substrate;

fig. 7 is a sectional view showing a bonding example between a first substrate and a second substrate;

FIG. 8 is a plan view showing a modular display panel;

FIGS. 9 and 10 illustrate a display device having a rollable display panel according to an embodiment of the invention;

fig. 11 shows the structure of an elastic unit according to a first embodiment of the present invention;

fig. 12 and 13 show the structure of an elastic unit according to a second embodiment of the present invention.

Detailed Description

For purposes of simplicity and clarity, the elements in the figures are not necessarily drawn to scale. The same reference numbers in different drawings identify the same or similar elements and, thus, perform similar functions. Moreover, descriptions and details of well-known steps and elements are omitted for simplicity of the description. Furthermore, in the following detailed description of the present invention, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it is understood that the invention may be practiced without these specific details. In other instances, well known methods, procedures, components, and circuits have not been described in detail as not to unnecessarily obscure aspects of the present invention.

Examples of embodiments are further illustrated and described below. It will be understood that the description herein is not intended to limit the claims to the particular embodiments described. On the contrary, it is intended to cover alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.

It will be understood that, although the terms "first," "second," "third," etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the spirit and scope of the present invention.

It will be understood that when an element or layer is referred to as being "connected to" or "coupled to" another element or layer, it can be directly on, connected or coupled to the other element or layer or one or more intervening elements or layers may be present. In addition, it will be further understood that when an element or layer is referred to as being "between" two elements or layers, it can be the only element or layer that is between the two elements or layers, or one or more intervening elements or layers may also be present.

For ease of describing the relationship of one element or feature to another element or feature shown in the figures, spatially relative terms such as "below … …", "below … …", "lower", "below … …", "above … …", "upper", and the like, may be used herein. It will be understood that these spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, when the device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, the example terms "below … …" and "below … …" may encompass both an above and below orientation. The device may be otherwise oriented, such as by rotating through 90 degrees or at other orientations, and the spatially relative descriptors used herein should be interpreted accordingly.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. It will be further understood that the terms "comprises" and/or "comprising," when used in this application, specify the presence of stated features, integers, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, operations, elements, components, and/or groups thereof. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items. When appearing before a column of elements, expressions such as "at least one of" may modify an entire column of elements rather than modifying a single element of the column.

Unless defined to the contrary, all terms used herein, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which the inventive concepts belong. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. The present invention may be practiced without some or all of these specific details. In other instances, well known process structures and/or processes have not been described in detail in order not to unnecessarily obscure the present invention.

Hereinafter, a display device having a rollable display panel according to the present invention will be described in detail with reference to the accompanying drawings.

Hereinafter, as an example of implementing a display device having a rollable display panel, an organic electroluminescent display device will be described. However, the present invention is not limited thereto. Any display device capable of realizing a display device having a rollable display panel can be applied to the present invention.

Fig. 1 is a schematic block diagram of an organic electroluminescent display device according to an embodiment of the present invention. Fig. 2 shows a schematic circuit diagram of a sub-pixel. Fig. 3 shows a structure of a sub-pixel according to an embodiment of the present invention.

As shown in fig. 1, the organic electroluminescent display device according to an embodiment of the present invention includes an image processing unit 110, a timing control unit 120, a data driver 140, a scan driver 130, and a display panel 150.

The image processing unit 110 may be used to output a DATA enable signal DE along with a DATA signal DATA supplied from the outside.

The image processing unit 110 may be configured to output at least one of a vertical synchronization signal, a horizontal synchronization signal, and a clock signal in addition to the data enable signal DE. These signals are omitted from the drawings for convenience of explanation.

The timing control unit 120 may be configured to receive the DATA signal DATA in addition to the driving signals including the DATA enable signal DE or the vertical synchronization signal, the horizontal synchronization signal, and the clock signal from the image processing unit 110. The timing control unit 120 may be configured to output a gate timing control signal GDC for controlling an operation timing of the scan driver 130 based on the driving signal and output a data timing control signal DDC for controlling an operation timing of the data driver 140 based on the driving signal.

The DATA driver 140 may be operative to sample and latch the DATA signal DATA provided from the timing control unit 120 in response to receiving the DATA timing control signal DDC provided from the timing control unit 120, and then convert the sampled and latched DATA signal into a gamma reference voltage and output the gamma reference voltage. The DATA driver 140 outputs the DATA signal DATA via the DATA lines DL1 to DLn. The data driver 140 may be implemented as an IC (integrated circuit).

The scan driver 130 may be used to output a scan signal while shifting the level of the gate voltage in response to receiving the gate timing control signal GDC provided from the timing control unit 120. The scan driver 130 outputs scan signals through the scan lines GL1 to GLm. The scan driver 130 may be implemented as an IC integrated circuit, or may be formed in the display panel 150 in a GIP (gate in panel) manner.

The display panel 150 may be used to display an image based on the DATA signal DATA and the scan signal supplied from the DATA driver 140 and the scan driver 130. The display panel 150 includes subpixels SP operable to display an image.

The sub-pixel may be implemented as a top emission type, a bottom emission type, or a double side emission type according to its structure.

The sub-pixels SP may include red, green, and blue sub-pixels. Alternatively, the sub-pixels SP may include a white sub-pixel, a red sub-pixel, a green sub-pixel, and a blue sub-pixel. The sub-pixel SP may have at least one different light emitting region according to its light emitting characteristic.

As shown in fig. 2, one sub-pixel includes a switching transistor SW, a driving transistor DR, a capacitor Cst, a compensation circuit CC, and an organic light emitting diode OLED.

The switching transistor SW is used to perform a switching operation in response to receiving a scan signal supplied through the first scan line GL1 such that a data signal supplied via the first data line DL1 is stored in the capacitor Cst as a data voltage. The driving transistor DR serves to flow a driving current between the first power line EVDD and the second power line EVSS according to the data voltage stored in the capacitor Cst. The organic light emitting diode OLED operates to emit light using the driving current from the driving transistor DR.

The compensation circuit CC may be a circuit added within the sub-pixel to compensate for the threshold voltage of the driving transistor DR. The compensation circuit CC may comprise at least one capacitor. The configuration of the compensation circuit CC is greatly different according to its compensation method. The following are examples thereof.

As shown in fig. 3, the compensation circuit CC includes a sensing transistor ST and a sensing line VREF. The sensing transistor ST is connected to a node (hereinafter referred to as a sensing node) between the source line of the driving transistor DR and the anode of the organic light emitting diode OLED. The sensing transistor ST serves to supply an initialization voltage (or a sensing voltage) transmitted through the sensing line VREF to a sensing node or sense a voltage or current of the sensing node.

The switching transistor SW includes a first electrode connected to the first data line DL1 and a second electrode connected to the gate electrode of the driving transistor DR. The driving transistor DR has a first electrode connected to the first power line EVDD and a second electrode connected to the anode of the organic light emitting diode OLED. The capacitor Cst has a first electrode connected to the gate electrode of the driving transistor DR and a second electrode connected to the anode electrode of the organic light emitting diode OLED. The organic light emitting diode OLED has an anode connected to the second electrode of the driving transistor DR and a cathode connected to the second power line EVSS. The sensing transistor ST has a first electrode connected to the sensing line VREF and a second electrode connected to an anode electrode of the organic light emitting diode OLED.

As used herein, the first electrode and the second electrode are defined as a source electrode and a drain electrode, respectively, or as a drain electrode and a source electrode, respectively, based on the type of the transistor.

The operation time of the sensing transistor ST may be similar to or different from that of the switching transistor SW according to the configuration of the compensation circuit or the compensation algorithm. In one example, the switching transistor SW has a gate electrode connected to the first sub-scanning line GL1a, and the sensing transistor ST has a gate electrode connected to the second sub-scanning line GL1 b. In another example, the first sub-scanning line GL1a connected to the gate electrode of the switching transistor SW and the second sub-scanning line GL1b connected to the gate electrode of the sensing transistor ST may be shared by the two transistors SW and ST.

The sensing line VREF may be connected to the data driver. In this case, the data driver may sense the sensing node of the sub-pixel during a non-display period or N frame (N is an integer of 1 or more) periods of an image, or in real time, and then may cause the compensation circuit to perform compensation based on the sensing result. In one example, the switching transistor SW and the sensing transistor ST may be turned on at the same time. In this case, the sensing operation via the sensing line VREF and the data output operation for outputting the data signal are distinguished from each other based on time division by the data driver.

Further, the data to be compensated based on the sensing result may include a digital-based data signal, an analog-based data signal, a gamma voltage, or the like. In addition, the compensation circuit for generating the compensation signal or the compensation voltage based on the sensing result may be implemented inside the data driver or the timing control unit, or may be implemented as a separate circuit.

In fig. 3, a sub-pixel having a 3T (transistor) 1C (capacitor) structure including a switching transistor SW, a driving transistor DR, a capacitor Cst, an organic light emitting diode OLED, and a sensing transistor ST is illustrated as an example. However, the present invention is not limited thereto. When the compensation circuit CC is added in the sub-pixel, the sub-pixel may include a 3T2C, 4T2C, 5T1C, or 6T2C structure, etc.

Since the organic electroluminescent display device as described above does not require a backlight unit, the organic electroluminescent display device may have a display panel thinner than a liquid crystal display. In addition, since the display panel of the organic electroluminescent display device may be as thin and flexible as possible, the display panel may be bent or curved. In addition, the panel may be deformed into a rolled shape (rolled shape), or the like.

Therefore, in recent years, various types of mechanical structures for a display panel accommodating an organic electroluminescent display device have been designed. Hereinafter, a structure of a display panel that can be wound or stretched to realize a display device having the windable display panel will be described.

Fig. 4 is a top view of an exemplary display panel according to an embodiment of the present invention. Fig. 5 is a cross-sectional view of an exemplary display panel according to an embodiment of the present invention. Fig. 6 is a sectional view showing an etching example of the first substrate. Fig. 7 is a cross-sectional view of the first substrate and the second substrate bonded together. Fig. 8 is a plan view of a modular display panel.

As shown in fig. 4 to 8, the display panel 150 according to an embodiment of the present invention includes a first substrate GLS, an intermediate layer IL having a display area AA including a plurality of pixels, and a second substrate MS.

The intermediate layer IL has an adhesive layer ADL in addition to a plurality of pixels constituting the display area AA. The plurality of pixels may include sub-pixels configured to emit red R, white W, blue B, and green G light beams. However, the present invention is not limited thereto. The adhesive layer ADL may be made of an adhesive material capable of bonding between the first substrate GLS and the second substrate MS, and seals the intermediate layer IL between the first substrate GLS and the second substrate MS.

The first substrate GLS may be made of glass or resin. The thickness of the first substrate GLS may be 0.01mm to 0.2 mm.

From the experimental results, it was confirmed that when the thickness of the first substrate GLS is as thin as 0.01mm to 0.1mm, the first substrate can be wound in a roll state or can be unwound in an extended state even if the first substrate is made of glass instead of resin.

The first substrate GLS has an etched region (etched portion) GLS1 and an unetched region (unetched portion) GLS 2. On the unetched region GLS2, pads for connection with an external substrate may be provided. The unetched region GLS2 has an elongated or elongated rectangular shape (elongated rectangular shape) and may correspond to the non-display region NA.

In the unetched region GLS2, the first substrate may be connected to an external substrate. The unetched parts enhance the stiffness of the substrate. For this reason, it is desirable that the unetched region GLS2 occupies 5 to 10% of the total area of the first substrate GLS. Further, the unetched regions GLS2 have higher stiffness than the etched regions GLS 1. For this reason, the thickness t2 of the unetched region GLS2 is preferably selected to be in the range of 0.1mm to 0.2 mm.

The first substrate is partially removed by an etching process except the unetched region GLS2 to form an etched region GLS 1. The etched area GLS1 is provided to relieve tensile stress that the first substrate GLS may be subjected to when the display panel 150 is wound into a roll state or unwound into an extended state. For this, it is preferable that the thickness t1 of the substrate in the etched region GLS1 is selected from the range of 0.01mm to 0.1 mm.

The second substrate MS may be made of metal. The thickness of the second substrate MS may be selected from a range of 0.01mm to 0.2 mm. The second substrate MS absorbs, disperses and relieves tensile stress that the first substrate GLS may be subjected to when the display panel 150 is wound in a roll state or unwound in an extended state.

From the experimental results, it can be confirmed that when the thickness of the second substrate MS is as thin as 0.01mm to 0.2mm, the second substrate effectively absorbs, disperses and alleviates tensile stress that the first substrate GLS may be subjected to when the display panel 150 is wound into a roll state or unwound into an extended state.

Since the second substrate MS is made of a metal material, the second substrate is more resistant to impact than the first substrate GLS. As a result, the second substrate MS can be made larger than the first substrate GLS. That is, the second substrate MS may have the protrusion region GP, in which the second substrate protrudes outward, compared to the first substrate GLS. The protruding regions may be present at one or more locations. In addition, the protrusion region GP of the second substrate MS may effectively serve to protect the corner of the first substrate GLS from an impact that the first substrate GLS may receive.

Meanwhile, the display panel 150 may be electrically connected to the timing control unit 120, the data driver 140, the scan driver 130, and the like (the image processing unit or the power supply unit is not shown). As a result, the display panel is modularized as shown in fig. 8.

The scan driver 130 is formed in the display panel 150 in the form of an intra-panel gate. The data driver 140 is implemented in the source substrate 145. The timing control unit 120 and the like are mounted in the control substrate 125.

In order to wind the display panel 150 in a roll state, the scan driver 130 may be preferably formed to the left and/or right of the display area AA in a GIP (gate in panel) manner. However, the present invention is not limited thereto. Further, the data driver 140 may be mounted in the source substrate 145 serving as a flexible circuit board, and the timing control unit 120 and the like may be mounted in the control substrate 125 serving as a printed circuit board. However, the present invention is not limited thereto. In addition, the source substrate 145 and the control substrate 125 may be connected to each other via a cable. However, the present invention is not limited thereto.

Hereinafter, a mechanical structure for implementing a display device having a rollable display panel will be described.

Fig. 9 and 10 illustrate a display device having a rollable display panel according to an embodiment of the present invention.

As shown in the drawings, the display device having a rollable display panel according to an embodiment of the present invention includes a display panel P for displaying an image, and a rolling and unrolling mechanism (rolling and unrolling mechanism) for rolling up or unrolling down the display panel P.

The winding and unwinding mechanism includes: a display panel roller 220 to which the display panel P is fixed, the display panel roller 220; a support frame 210 to which the display panel roller is rotatably coupled; a driving motor 230 for providing a driving force for rotating the display panel roller 220 with respect to the support frame; and an elastic unit 240, the elastic unit 240 for providing an elastic force to assist the upward winding of the display panel roll 220.

A weight bar 250 is coupled to a lower end of the display panel P. The weight lever 250 keeps the entire surface of the display panel flat. The weight levers serve to pull the display panel P downward so that the display panel P can be smoothly lowered.

The weight lever 250 may be made of a metal material, a synthetic resin material, a natural material, or a combination thereof.

For example, the weight lever 250 may be formed of a laminate of a metal material layer and a synthetic resin material layer. Alternatively, the weight lever 250 may be a laminate of a metal layer and a natural wood layer or a stone layer.

The weight lever 250 may be attached to the display panel P using an adhesive. Alternatively, the weight lever may be fixed to the display panel P using a fastening member.

The driving motor rotates the display panel roller 220 in two directions. As shown in fig. 10, when the driving motor rotates the display panel roller 220 clockwise, the display panel P is unfolded downward. As shown in fig. 9, when the driving motor rotates the display panel roller 220 counterclockwise, the display panel P is wound upward.

As shown in fig. 10, when the display panel P is unfolded downward, the power required for the driving motor 230 for the unfolding-downward operation may be reduced due to the weight of the display panel P and the weight lever 250.

However, as shown in fig. 9, when the display panel P is wound upward, the driving motor 230 may require more power due to the weight of the display panel P and the weight lever 250.

Thus, the specification of the driving motor 230 may be adapted to the force required to wind the display panel P upward.

However, for a large-sized display panel P, the weight of the display panel P and the weight of the weight lever 250 increase the size and power consumption of the driving motor 230 to generate the required driving force for winding up the display panel P.

Thus, according to the present invention, the size of the driving motor 230 can be reduced by winding up the display panel P using the elastic force stored in the elastic unit 240 together with the driving force of the driving motor 230.

As shown in fig. 10, when the display panel P is lowered, elastic force is stored in the elastic unit 240 due to the weight of the weight lever 250. As shown in fig. 9, when the display panel P is lifted, the elastic force stored in the elastic unit 240 acts in a direction of winding up the display panel to assist the winding up of the display panel roll 220.

In other words, when the display panel roller 220 rotates in a direction to lower the display panel P, the elastic unit 240 stores therein an elastic force generated by the load of the weight bar. Then, the elastic unit 240 releases the stored elastic force to help the display panel roller 220 lift the display panel P.

Further, according to the present invention, the driving motor 230 and the elastic unit 240 are disposed within the display panel roller 220 and are disposed at positions adjacent to both ends of the display panel roller 220, respectively.

With the above structure, the size of the entire display device having the rollable display panel can be reduced, and the appearance thereof can also be improved.

Further, when the motor winds up the display panel P, the rotational force from the motor and the elastic unit may be transmitted to both ends of the display panel roller 220, respectively. This allows the display panel P to be uniformly wound on the display panel roll 220.

Fig. 11 shows the structure of the elastic unit according to the first embodiment of the present invention.

The elastic unit according to the first embodiment of the present invention includes a torsion spring 242.

The torsion spring 242 serves to convert torque into elastic force. Thus, according to the present invention, it is possible to store elastic force at the time of downward expansion of the display panel using a relatively simple structure of the torsion spring. In addition, the degree of torsion of the torsion spring 242 may be controlled to adjust the magnitude of the stored elastic force.

One end of the torsion spring 242 is fixed to the support frame 210, and the other end of the torsion spring is fixed to the display panel roller 220.

When the display panel roller 220 rotates in the downward-spreading operation, a torque is applied to the torsion spring 242, and the torque is converted into an elastic force. Then, the elastic force is stored in the torsion spring 242.

That is, when the display panel roller 220 rotates so that the display panel P descends, elastic force is stored in the torsion spring 242. Then, the elastic force stored in the torsion spring 242 relieves the required power of the display panel roller 220 for winding up the display panel P.

Accordingly, the elastic force stored in the torsion spring 242 serves to wind the display panel P upward, together with the driving force of the driving motor 230. This allows for a relatively small capacity or size of the drive motor 230.

In addition, the apparatus of the present invention preferably further comprises a sensor 235 for sensing the amount of rotation of the driving motor 230. The sensor 235 senses a rotation angle of the display panel roller 220 or the driving motor 230.

Based on the amount of rotation sensed by the sensor 235, the control unit may control the operation and stop of the driving motor 230.

The support frame includes two

end plates

212 and 214 coupled to both ends of the display panel roller 220, respectively.

In the illustrated embodiment, the driving motor 230 is disposed at the left side of the display panel roller 220, and the elastic unit is disposed at the right side of the display panel roller 220. The left side plate 212 is connected to the driving motor 230, and the right side plate 214 is connected to the elastic unit.

In this regard, the hollow shaft 215 may be coupled to the right side plate 214. The hollow shaft 215 is inserted into the display panel roller 220. A torsion spring 242 is wound around the outside of the hollow shaft 215. The torsion spring is disposed inside the display panel roller 220. One end of the torsion spring 242 is fixed to the hollow shaft 215, and the other end of the torsion spring 242 is fixed to the display panel roller 220.

The hollow shaft 215 is rotatable relative to the right side plate 214 and is rotatably coupled to a specific location of the right side plate. When the hollow shaft 215 is rotated in place, torque may be applied to the torsion spring 242. Thus, by rotating the hollow shaft 215 relative to the right side plate 214, the elastic force (or tension) stored in the torsion spring 242 can be adjusted.

Further, between the driving motor 230 and the elastic unit, a printed circuit board PCB of the display panel P may be disposed. The printed circuit board PCB may be implemented as the control substrate 125 as described above.

The wiring of the printed circuit board PCB connected to the display panel P may be drawn out from the display panel roll 220 through the hollow shaft 215.

The wiring for transmitting signals to the display panel P or supplying power to the display panel P must be connected to the display panel. Such wiring can be drawn out to the outside through the inside of the display panel roller, thereby securing durability of the wiring and improving reliability of the product.

In this case, when the display panel P is wound up or unwound down to the midpoint of the maximum stretching amount, the wiring remains unwound (unwound). It is desirable to reduce the entanglement of the wires when the display panel is fully entangled or fully unwound.

For example, when the display panel roller 220 rotates three times, i.e., three times 360 degrees, the display panel P is completely lowered. When the display panel is rotated three times in the opposite direction, the display panel P is completely wound. In this case, it is desirable to configure the wiring as follows: the wire is in a neutral state (unwound) when the roller is rotated 1.5 times in the clockwise or counterclockwise direction; when the display panel roller 220 is completely wound, the wire is wound by 1.5 turns; in contrast, when the display panel roller 220 is completely unwound, the wire is wound in the opposite direction for 1.5 turns.

The elastic unit according to the second embodiment of the present invention serves to store elastic force using a compression spring.

As shown in the drawings, an elastic unit according to a second embodiment of the present invention includes: a spring housing 216 secured to the right side plate 214 of the support frame; a compression spring 260 disposed inside the spring housing 216; a compression plate 264 coupled to the spring to be axially slidable within the spring housing 216 along the spring housing 216; a ball screw 262 coupled to the compression plate 264; and a ball nut (ball nut)224 fixed to the display panel roller 220 and screw-coupled to the ball screw 262.

As shown in fig. 12, when the display panel roller 220 rotates to lower the display panel P, the ball nut 224 rotates with respect to the ball screw 262 along with the roller. Thus, the ball screw moves rightward, and thus the compression plate 264 moves rightward, thereby compressing the compression spring 260.

In contrast, as shown in fig. 13, when the display panel roller 220 rotates to wind the display panel P upward, the ball nut 224 rotates in a direction opposite to the previous direction with respect to the ball screw 262, so that the compression plate 264 moves leftward. At this time, the upward winding operation of the display panel roller 220 is assisted by the elastic restoring force previously stored in the compression spring 260.

Although the ball screw 262 is illustrated as having a small diameter in the drawings, the ball screw 262 may have a large outer diameter and a hollow portion may be formed inside the ball screw 262.

When the ball screw 262 is formed in a hollow shape, as described in the first embodiment, the wiring of the printed circuit board PCB connected to the display panel may be drawn out through the hollow ball screw 262.

The construction using the compression spring 260 is more complicated than the construction using the torsion spring. However, for the configuration using the compression spring, the outer diameter of the spring changes less at the time of compression and extension of the spring than the configuration using the torsion spring.

In the description above, numerous specific details are set forth in order to provide a thorough understanding of the present invention. The present invention may be practiced without some or all of these specific details. Examples of embodiments are illustrated and described above. It will be understood that the description herein is not intended to limit the claims to the particular embodiments described. On the contrary, the invention is intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope of the invention as defined by the appended claims.

Claims

1. A display device having a rollable display panel, comprising:

the display panel is used for displaying images;

a display panel roller to which the display panel is fixed, the display panel roller being elongated;

a support frame to which the display panel roller is rotatably coupled;

a driving motor for rotating the display panel roller with respect to the support frame, wherein the rotation of the display panel roller causes the display panel to be wound up on or unwound down from the display panel roller; and

an elastic unit for providing an elastic force to assist in winding up the display panel on the display panel roller,

wherein the driving motor and the elastic unit are disposed in the display panel roller and are respectively disposed at positions adjacent to opposite ends of the elongated display panel roller.

2. The display device with the rollable display panel of claim 1, further comprising a weight bar coupled to the display panel at a bottom of the display panel.

3. The display device having the rollable display panel according to claim 1, wherein the elastic unit is to store elastic force during the process that the display panel is unwound downward from the display panel roll, and to release the stored elastic force to assist in rolling up the display panel on the display panel roll.

4. The display device having the rollable display panel according to claim 3, wherein the elastic unit comprises a torsion spring.

5. The display device with the rollable display panel according to claim 1, wherein the elastic unit comprises:

a hollow shaft connected to the support frame; and

a torsion spring having one end fixed to the hollow shaft and the other end fixed to the display panel roller.

6. The display device having the rollable display panel according to claim 5, wherein the tension of the torsion spring is adjustable by adjusting a fixed state of the hollow shaft.

7. The display device with a rollable display panel according to claim 1, wherein a circuit board is provided in the display panel roll between the driving motor and the elastic unit, wherein a wire connected to the display panel is pulled out of the display panel roll through the elastic unit.

8. The display device having the rollable display panel according to claim 3, wherein the elastic unit comprises a compression spring.

9. The display device with the rollable display panel according to claim 1, wherein the elastic unit comprises:

a spring housing secured to the support frame;

a compression spring disposed within the spring housing;

a compression plate coupled to the compression spring to be axially slidable along the spring housing within the spring housing;

a ball screw coupled to the compression plate; and

a ball nut fixed to the display panel roller, wherein the ball screw is threadedly coupled to the ball nut.

10. The display device with a rollable display panel according to claim 9, wherein the ball screw is hollow so that wiring connected to the display panel passes through the ball screw.

11. A display device having a rollable display panel according to claim 1, further comprising a sensor for sensing the degree of rotation of the display panel roller.

12. The display device with the rollable display panel according to claim 1, further comprising a wire for transmitting a signal to the display panel or supplying power to the display panel, wherein the wire is drawn out to the outside through the inside of the display panel roll.

13. The display device having a rollable display panel according to claim 12, wherein the wiring remains unwrapped when the display panel is rolled up or rolled down to a midpoint of maximum extension.